I was a caver a long time ago and did horizontal, vertical, and even paddled a rubber raft in an underground stream (with a guy who couldn't swim). Also been through one emergency, similarly caused by heavy rains. Our strongest female caver had her legs give out while at the bottom of a 510 foot pit. A local caver with rescue experience physically pulled her up and out. I really thought those kids were goners or at least most of them. Between the pumps, the SEALS, and the rain letting up, they all got out. And then the pumps failed. Just incredible.